Electric switch



arch EL 11925 W. K. RANKIN ELECTRIC SWITCH Filed Nov. 1 1922 2Sheets-Sheet l Invemtwt .William Kfiankin 3 b3 HisAttmrneg.

w. K. RANKIN ELECTRIC sw wcu FildNov 14s. 1922 2 Sheets-Sheet 2 Fig. 5a

Ihvevwtor:

His Attorn eg Patented Mar. El, 19250 cairn sira WILLIAM K. RANKIN, 0FSCHENECTADY,'NEW YORKJ'ASSIGN OR TO GENERAL ELEC- TRIS COMPANY, ACORPORATION OF NEW YORK.

. nnno'rniea SWITCH.

Application filed N ovember le, 1922. Serial No. 600,804.

To all cello m. it-ma l concern:

Be it known that I, WILLIAM K. RANKIN, a citizen of'the United States,residing at Schenectady, in the county of Schenectady, State of NewYork, have invented certain new and useful Improvements in ElectricSwitches, of which the following is a specification.

My invention relates to electric switches,

and especially to switches having contacts separable within a closedchamber --which contains an insulating liquid.

In theoperation of fiuid break switches, the-arc drawn between theswitch contacts upon their separation produces intense local heating ofthe insulating liquid ambient the arcpath thereby vaporizing a part of.

this liquid and creating within the cham her a pressure which'operatesboth to suppress the arc and to accelerate the separation of thecontacts by its piston action on the movable contact.

One of the major objects of my invention is to provide at switch ofv theabove described type wherein a certain amount of liquid may be usedrepeatedly during circuit breaking operations, provision being made forthe recovery of this liquid after each operation so that the same may beused again. To this end in the embodiment of my invention. hereindisclosed, I provide a receptacle having a reservoir in its lowerportion adapted to contain a small quantity of liquid which is one suchas water that is not-permanently affected by heat. l llectrodes are ablebeneath the surface of this liquid and the portion of the receptacleabove the sump is formed as a condensing chamber whereby the liquidvaporized by the arc is condensed after the arc has been extinguishcdand returned to the sump.

i In order to facilitates its cooling and condensing action and toinsulate the conducting portions thereof, I submerge the receptacle inan insulating liquid which also. surrounds the main contacts of theswitch.

Numerous other objects and advantages of my invention will be in partobvious and in part explained in the following description taken .inconnection with the accompanying drawing in which Fig. 1 shows avertical section of a single pole switch containing one embodiment of myinvention,

provided which are separ some of the parts being cut away and othersshown in elevation. Fig. 2 is a sectional view of a modified form ofreceptacle or explosion chamber wherein additional strength is attainedby imbedding rings of metal the chamber is formed, carebeing taken tomaintain a suflicient dielectric strength of insulation betweencontacts, and Fig. 3 is a view similar to Fig. 1, showing a modifiedform of switchfor use on high power circuits, where the intensity of thearc and :the amount. of vapor formed will cause a l'ngh pressure to beexerted against the walls of the explosion chamber, the construction ofthe chamber being such as to necessitate a modified arrangement for theinsulation of the contacts.

.In Fig. 1 is shown a tank adapted to contain an insulating liquid andin which rests an insulator 12 adapted to support a contact 13 and anexplosion chamber casing 14. The explosion chamber casing 14 is composedof insulating material, the inner surface of which is corrugated,thereby forming small annular condensingchambers 15. The stationaryelectrode 16 is cupshaped and forms the lower portion or sump of theexplosion chamber.

The cover 20 of the tank 10 is constructed to permit the passage of theinsulating operating rod 21 and also the insulating bushings 22 throughwhich the switch leads 23 and 24 pass. The switch lead 24 is hollow inform and is fitted with a side connection and -a stopcock 25 to whichmeans may be attached to admit liquid 26 to the explosion chamber. Thenormal levels of the liquid in tank 10 and explosion chamber 14 areindicated by the shading. \Vhile various liquids may be used in theexplosion chainber, I prefeiwto employ distilled water or in case theswitch is used where the tempera-- ture falls below freezing, I mayemploy a. mixture of water and glycerine.

The contact mechanism of the switch con1- prises primary and secondarycontact members. The primary contact lever 30 is pivoted at 31 andsupports a contact brush 32 adapted to cooperate with a stationarycontact 13. The secondary contact lever 83 is pivoted at 34 and isconnected to the operating rod 38 of the secondary contact 38 through alink 35 and pins 36 and 37. The

in the insulating material of which contact levers and 33 are gearedtogether and are operated by means of the insulat-, ing rod 21.. Theoperating rod 38 enters the explosion chamber through a stufiing beprovided in theaperture 10.

rovision is made for making the final break in the circuit at themovable electrode 38 by use of a sliding contact l5 which is inelectrical connection with the stationary contacb 16. l he movement or"this sliding contact 415 to follow the movable electrode 38 is caused bythe pressure of the spring 16 which is compressed when the contactsclose. The distance which the slid- ,ing contact may move in the upwarddirection is limited by its head striking against the under surface ofthe stationary contact 16. A cap 17 is provided to form a seat for thespring 46 and to make it unnecessary to seal the bearing of the slidingcontact 15. Qpening 51 is provided in the bottom of the stationarycontact 16 for per-. mitting free movement of the sliding coutaet 45.

' An hydraulic dash pot is attached to the chamber cover 11, the piston(31 of which is connected to the secondary contact lever by the link 62.An aperture in the dash pot body is designed to permit fl-e movement oithe piston 61 during the first part of its downward stroke. dis thepiston (51 passes below the aperture 55 near the end of the stroke, thedash pot serves a cushion and the contact lever is brought to restwithout shock.

Low resistance connection is maintained between the chamber cover 11 andthe contact member 30 and lever by the use of flexible leads 65.

Where it is desired to use an explosion chamber adapted to withstandhigh internal pressure. I can )rovide reinlbrcin means 1 1 L O for theinsulated explosion chamber. @no such means is shown in 2 wherein 52represents an inner insulating condensing casing and 53 an outer shellformed of insulation and reinforced by interlocked annular metallicmembers 54.

Fig. 3 I have shown another arrangement by which the explosion chambermay be made to withstand high internal pressure. in this term of myinvention the metal casing 1 1/1 is a modified *l'orm ol. the casingshown in Fig. 2 and is adapted to receive a removable condensingliningill?) which is a modified .ioriu of that shown in The explosion'chambcr casing is supported from the tank 10 by an insulator 111 and isheld, by a clamping member 150, in a position permitting removal of theexplosion chamber. An example of such a fastening means is shown in thepatent to Bali, 915,671. Jan. 4-. 1910. The primary contact plat 113 isin electrical contact with the explosion chamber casing 11 1-. The ex-'01" the piston (ll. and the hearth the piston is compiplosion chambercasing is provided with a metallic cover 14-1 to which the hollow lead24: is fastened. A lead 22) is connected to the contact mechanismsupport 1412 which is supported from the cover 1 11 by the insulater 113 and the insulating bushing 1 1 1. Gas tight connections are providedbetween the insulating bushing 14- 1 and the (3X]')l0-' sion chamber115. The stuiling box 1 18 is provided "for the purpose of preventingthe escape of gas through the opening provided for the movable contact38.

In operating under load from the closed position of the switches shownin Figs. 1 and 3, the operating rod is raised by operating meansexternal to the switch. lhe

operating means not shown but may be of any well known constructionsuch. for example as that shown in patent to Hewlett and Button 973,657,bet. 2:), 1910. Movement of the primary brush 32 away from its contactwill cause all the current to flow through the auxiliary electrode 38.The insulating liquid 11 will extinguish any are which may tend to101111 between the brush 32 and its cooperating contact and introduce ahigh resistance to the passage of current between brush and contact.

After the separation of the primary contacts the electrodes and '3 areseparated beneath the surface o l liquid 26. ifhis results in theocrhiation o1 he liquid which grea s the pressure This presctrode B5sure assists in through the openin rapid separation or incipient are wseparation of these c tinguished and tn tion of water in many respectsH1111 to liicholson The hot vapo s sides of the r chamber 15' will indliquid so formed will flow to ie sumo. thus being available 'l'ori'urther on ":nion ml the switch. I A 1:

The dash po 0 is i=.'orid :d u in an opent (3 ing designed o lf'djzuorcnn-iu ssociztlcd sccoiuh ary contact lever Ill; during the lirstpart of the opening niorcincnt oi the switch. I the piston {51. passesinc opening 35 in l\. downward movement. hour-yer, lhc oil lll" rd and lol'wll 1121;) in Shchollom pm'init out through a small o of the dash potthus sci piston and bring 1 3H lo -1l without shock. in H rziliim oi theswitch the opcuii us to pcrmit rapid acceleration of h swondar -i (HIPtact 38 during the latter l'dli'b ii its closing movement, tlie shockincident to closure of the switch being absorbed by the spring 46 whichsupports the movable contact 45.

In closing the switch the operations-are reversed. The operating rod israised to cause moven ent to close botli the primary brush 32 andthemovable electrode 38. In so doing the movable electrode 38 contacts withthe sliding contact i5 and establishes the circuit before the primarybrush makes contact. Between the time that the movable electrode38 hasmade contact with the sliding contact and the instant of final clos-'ing at the primary contact brush 32, both the movable electrode 38 andthe sliding contact 45 move downwardly, contact between the two beingmaintained by the spring l6.

Switches of the class .described may be used for a large variety ofconditions of service and my invention in its broader aspects is notlimited to the particular constructions shown herein. lVhile I haveshown the contact levers 30 and 33 as connected together by means ofinter-meshing gears, it is apparent that other suitable ployed forsecuring the desired mechanical movenumt. Other changes apparent tothose skilled in the art may be made without departing from the scope ofmy invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is,-

1. In a switch, a sealed explosion chamber comprising a reservoir in itslower portion and a. condensing chamber in its upper portion.

A switch of the type whereina circuit broken by the separation ofcontacts in proximity to a liquid which is vaporized but not permanentlyafiectedthereby, rlmracterizml by the fact that means are pro- \ided forcondensing the vapor of said liquid.

3'. A switch of the type wherein a circuit is broken 'by the separationof contacts beneath the surface of a liquid which is vaporized but notpermai'wntly affected thereby, characterized by the fact that means areprovided 'l'or condensing the vapor of said liquid.

-'l-. A switch of the type wherein a circuit is broken by the separationof contacts in a reservoir containing a liquid which is vaporized butnot permanently affected thereby, characterized by the fact that meansare provided for the condensation of the vapor of said liquid and forthe return of the condensed liquid to said reservoir.

In a switch havin an explosion chamber formed with a metallic reservoirin its lower portion, an electrode in said reservoir and electricallyconnected thereto, a metallic cover for said explosion chamber, meansconnectingsaid cover and reservoir a-nd.serV-..

11103115 ll'ltly be 6111- ing to insulate them from one another, an

said chamber.

7. The combination of a sealed container, contacts separable within saidcontainer but not completely withdrawable there-from, said contactsbeing separable in a liquid which is vaporized but not permanentlyaffected by the breaking of a circuit by said contacts, a tanksurrounding said container, said tank being adapted to contain aninsulating liquid within which said container is immersed.

8. The combination of a sealed container, secondary electrodes havingcontact surfaces separable in said container to break a circuit wherebyan are formed by the separation of said contacts creates pressure Withinsaid container, said surfaces remaining at all times within saidcontainer, a tank enclosing said container, said tank being adapted tohold a liquid container is immersed, and primary electrodes for carryingthe main load current separable in said liquid.

9. A switch comprising a sealed chamber containing a liquid, secondarycontact members separable within said liquid, said liquid beingvaporized but not permanently affected by the breaking of a circuit bysaid contact members, a tank enclosing said container, said tankbeing'adapted to hold a liquid within'which said container is immersed,and primary contact members mounted outside said chamber and separablewithin said tank.

10. A switch having a scaled explosion chamber adapted to contain an arcextinwithin which said guishing fluid, electrodes separable within saidchamber to break a circuit whereby an are formed by the separation ofsaid electrodes creates pressure within said chamber, and a terminalconnected to one of said electrodesthrough the wall of said chamber,said terminal being formed with a passage for the supply of fluid tosaid chan'iber.

11. A switch comprising a sealed chamber containing water, primarycontact members for carrying the main load current separable withoutsaid chamber, and secondary contacts within said chamber for breakingthe circuit whereby an are formed at said secondary contacts Vaporizessaid water and creates pressure to extinguish said are and to acceleratethe separation of said contacts.

12. A switch comprising a sealed chamber immersed in a cooling andlnsulatmg ;1 an arc ,i'ic separable W a circuit 7 will. vanerizesuppress if r I V 1 J. H'JizCPh' o l. hlllll. chamber acung c n vaporproduced and return the a Sealed chamber 7. 1;: a reser foir ill t r n m()l, cni aciaplci lo LODLdhi an a c c 1351 liquid, contac 'v separable nniber to break .cc formed will i 1 wall to form a liquid, means foroperating one of said con cts extending i'hrough a Wall ol said L1l1l)/L whereby upon 'lhe se 'iararrion of said contacts, in. pors producedby i'hc inlorrupiion of the circuit will acceicrale the separation ofsaid contacts and be condensed on ibe Walls of said chamber and returnedto said reservoir.

15. An electric switch comprising a sea led chamber provided with acorrugaicd Wall and containing water in the lower portion thereof,contacts arranged in the lower poriion of said chamber whereby any. areformed upon the Separation of said contacts be drawn in said liquid,means for ing' one of said coniacls cx'lencling wrench a Wall of saidchainl whercby upon lhe inierrupiion ol' the circuit by lhe ,irazion ofsaid contacts the vapor presproducod in said sealed chamber will'nguishing the arc and acceleraeparationof said contacts, said 3condensed by the cooling acsaid corrugated wall and returned 1e lowerportion oi :he chamber.

an witness whe eof have hereunto set an; 'icl tins eleventh day Novemberifigf ...'JAl,.J-v

1 r F e v JAJJULLLLL Dr.

All; rm, 1

